target: add struct spc_ops + initial ->execute_rw pointer usage

Remove the execute_cmd method in struct se_subsystem_api, and always use the
one directly in struct se_cmd.  To make life simpler for SBC virtual backends
a struct spc_ops that is passed to sbc_parse_cmd is added.  For now it
only contains an execute_rw member, but more will follow with the subsequent
commits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

6 files changed, 61 insertions, 22 deletions

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index e2df30867b13..720ed59834fc 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -375,9 +375,11 @@ static void fd_emulate_sync_cache(struct se_cmd *cmd)
         }
 }
 
-static int fd_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
-                u32 sgl_nents, enum dma_data_direction data_direction)
+static int fd_execute_rw(struct se_cmd *cmd)
 {
+        struct scatterlist *sgl = cmd->t_data_sg;
+        u32 sgl_nents = cmd->t_data_nents;
+        enum dma_data_direction data_direction = cmd->data_direction;
         struct se_device *dev = cmd->se_dev;
         int ret = 0;
 
@@ -550,6 +552,15 @@ static sector_t fd_get_blocks(struct se_device *dev)
         return div_u64(dev_size, dev->se_sub_dev->se_dev_attrib.block_size);
 }
 
+static struct spc_ops fd_spc_ops = {
+        .execute_rw             = fd_execute_rw,
+};
+
+static int fd_parse_cdb(struct se_cmd *cmd)
+{
+        return sbc_parse_cdb(cmd, &fd_spc_ops);
+}
+
 static struct se_subsystem_api fileio_template = {
         .name                   = "fileio",
         .owner                  = THIS_MODULE,
@@ -561,8 +572,7 @@ static struct se_subsystem_api fileio_template = {
         .allocate_virtdevice    = fd_allocate_virtdevice,
         .create_virtdevice      = fd_create_virtdevice,
         .free_device            = fd_free_device,
-        .parse_cdb              = sbc_parse_cdb,
-        .execute_cmd            = fd_execute_cmd,
+        .parse_cdb              = fd_parse_cdb,
         .do_sync_cache          = fd_emulate_sync_cache,
         .check_configfs_dev_params = fd_check_configfs_dev_params,
         .set_configfs_dev_params = fd_set_configfs_dev_params,
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index c2d4ccbb7133..eb94367380c1 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -514,9 +514,11 @@ static void iblock_submit_bios(struct bio_list *list, int rw)
         blk_finish_plug(&plug);
 }
 
-static int iblock_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
-                u32 sgl_nents, enum dma_data_direction data_direction)
+static int iblock_execute_rw(struct se_cmd *cmd)
 {
+        struct scatterlist *sgl = cmd->t_data_sg;
+        u32 sgl_nents = cmd->t_data_nents;
+        enum dma_data_direction data_direction = cmd->data_direction;
         struct se_device *dev = cmd->se_dev;
         struct iblock_req *ibr;
         struct bio *bio;
@@ -663,6 +665,15 @@ static void iblock_bio_done(struct bio *bio, int err)
         iblock_complete_cmd(cmd);
 }
 
+static struct spc_ops iblock_spc_ops = {
+        .execute_rw             = iblock_execute_rw,
+};
+
+static int iblock_parse_cdb(struct se_cmd *cmd)
+{
+        return sbc_parse_cdb(cmd, &iblock_spc_ops);
+}
+
 static struct se_subsystem_api iblock_template = {
         .name                   = "iblock",
         .owner                  = THIS_MODULE,
@@ -674,8 +685,7 @@ static struct se_subsystem_api iblock_template = {
         .allocate_virtdevice    = iblock_allocate_virtdevice,
         .create_virtdevice      = iblock_create_virtdevice,
         .free_device            = iblock_free_device,
-        .parse_cdb              = sbc_parse_cdb,
-        .execute_cmd            = iblock_execute_cmd,
+        .parse_cdb              = iblock_parse_cdb,
         .do_discard             = iblock_do_discard,
         .do_sync_cache          = iblock_emulate_sync_cache,
         .check_configfs_dev_params = iblock_check_configfs_dev_params,
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index cb4c6b1195d4..6e32ff6f2fa0 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -55,6 +55,7 @@
 
 static struct se_subsystem_api pscsi_template;
 
+static int pscsi_execute_cmd(struct se_cmd *cmd);
 static void pscsi_req_done(struct request *, int);
 
 /*      pscsi_attach_hba():
@@ -1081,17 +1082,20 @@ static int pscsi_parse_cdb(struct se_cmd *cmd)
         case WRITE_16:
         case WRITE_VERIFY:
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
-                break;
+                /* FALLTHROUGH*/
         default:
+                cmd->execute_cmd = pscsi_execute_cmd;
                 break;
         }
 
         return 0;
 }
 
-static int pscsi_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
-                u32 sgl_nents, enum dma_data_direction data_direction)
+static int pscsi_execute_cmd(struct se_cmd *cmd)
 {
+        struct scatterlist *sgl = cmd->t_data_sg;
+        u32 sgl_nents = cmd->t_data_nents;
+        enum dma_data_direction data_direction = cmd->data_direction;
         struct pscsi_dev_virt *pdv = cmd->se_dev->dev_ptr;
         struct pscsi_plugin_task *pt;
         struct request *req;
@@ -1259,7 +1263,6 @@ static struct se_subsystem_api pscsi_template = {
         .free_device            = pscsi_free_device,
         .transport_complete     = pscsi_transport_complete,
         .parse_cdb              = pscsi_parse_cdb,
-        .execute_cmd            = pscsi_execute_cmd,
         .check_configfs_dev_params = pscsi_check_configfs_dev_params,
         .set_configfs_dev_params = pscsi_set_configfs_dev_params,
         .show_configfs_dev_params = pscsi_show_configfs_dev_params,
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index d7e838287d89..d00bbe33ff8b 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -284,9 +284,11 @@ static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
         return NULL;
 }
 
-static int rd_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
-                u32 sgl_nents, enum dma_data_direction data_direction)
+static int rd_execute_rw(struct se_cmd *cmd)
 {
+        struct scatterlist *sgl = cmd->t_data_sg;
+        u32 sgl_nents = cmd->t_data_nents;
+        enum dma_data_direction data_direction = cmd->data_direction;
         struct se_device *se_dev = cmd->se_dev;
         struct rd_dev *dev = se_dev->dev_ptr;
         struct rd_dev_sg_table *table;
@@ -460,6 +462,15 @@ static sector_t rd_get_blocks(struct se_device *dev)
         return blocks_long;
 }
 
+static struct spc_ops rd_spc_ops = {
+        .execute_rw             = rd_execute_rw,
+};
+
+static int rd_parse_cdb(struct se_cmd *cmd)
+{
+        return sbc_parse_cdb(cmd, &rd_spc_ops);
+}
+
 static struct se_subsystem_api rd_mcp_template = {
         .name                   = "rd_mcp",
         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
@@ -468,8 +479,7 @@ static struct se_subsystem_api rd_mcp_template = {
         .allocate_virtdevice    = rd_allocate_virtdevice,
         .create_virtdevice      = rd_create_virtdevice,
         .free_device            = rd_free_device,
-        .parse_cdb              = sbc_parse_cdb,
-        .execute_cmd            = rd_execute_cmd,
+        .parse_cdb              = rd_parse_cdb,
         .check_configfs_dev_params = rd_check_configfs_dev_params,
         .set_configfs_dev_params = rd_set_configfs_dev_params,
         .show_configfs_dev_params = rd_show_configfs_dev_params,
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index a5bd0c0eba08..da441b2782ce 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -395,7 +395,7 @@ out:
         kfree(buf);
 }
 
-int sbc_parse_cdb(struct se_cmd *cmd)
+int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
 {
         struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
         struct se_device *dev = cmd->se_dev;
@@ -409,26 +409,31 @@ int sbc_parse_cdb(struct se_cmd *cmd)
                 sectors = transport_get_sectors_6(cdb);
                 cmd->t_task_lba = transport_lba_21(cdb);
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+                cmd->execute_cmd = ops->execute_rw;
                 break;
         case READ_10:
                 sectors = transport_get_sectors_10(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+                cmd->execute_cmd = ops->execute_rw;
                 break;
         case READ_12:
                 sectors = transport_get_sectors_12(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+                cmd->execute_cmd = ops->execute_rw;
                 break;
         case READ_16:
                 sectors = transport_get_sectors_16(cdb);
                 cmd->t_task_lba = transport_lba_64(cdb);
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+                cmd->execute_cmd = ops->execute_rw;
                 break;
         case WRITE_6:
                 sectors = transport_get_sectors_6(cdb);
                 cmd->t_task_lba = transport_lba_21(cdb);
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+                cmd->execute_cmd = ops->execute_rw;
                 break;
         case WRITE_10:
         case WRITE_VERIFY:
@@ -437,6 +442,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
                 if (cdb[1] & 0x8)
                         cmd->se_cmd_flags |= SCF_FUA;
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+                cmd->execute_cmd = ops->execute_rw;
                 break;
         case WRITE_12:
                 sectors = transport_get_sectors_12(cdb);
@@ -444,6 +450,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
                 if (cdb[1] & 0x8)
                         cmd->se_cmd_flags |= SCF_FUA;
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+                cmd->execute_cmd = ops->execute_rw;
                 break;
         case WRITE_16:
                 sectors = transport_get_sectors_16(cdb);
@@ -451,6 +458,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
                 if (cdb[1] & 0x8)
                         cmd->se_cmd_flags |= SCF_FUA;
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
+                cmd->execute_cmd = ops->execute_rw;
                 break;
         case XDWRITEREAD_10:
                 if ((cmd->data_direction != DMA_TO_DEVICE) ||
@@ -464,6 +472,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
                 /*
                  * Setup BIDI XOR callback to be run after I/O completion.
                  */
+                cmd->execute_cmd = ops->execute_rw;
                 cmd->transport_complete_callback = &xdreadwrite_callback;
                 if (cdb[1] & 0x8)
                         cmd->se_cmd_flags |= SCF_FUA;
@@ -486,6 +495,7 @@ int sbc_parse_cdb(struct se_cmd *cmd)
                          * Setup BIDI XOR callback to be run during after I/O
                          * completion.
                          */
+                        cmd->execute_cmd = ops->execute_rw;
                         cmd->transport_complete_callback = &xdreadwrite_callback;
                         if (cdb[1] & 0x8)
                                 cmd->se_cmd_flags |= SCF_FUA;
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 82946962796d..803ac5202fcd 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1865,7 +1865,7 @@ EXPORT_SYMBOL(transport_generic_request_failure);
 
 static void __target_execute_cmd(struct se_cmd *cmd)
 {
-        int error;
+        int error = 0;
 
         spin_lock_irq(&cmd->t_state_lock);
         cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
@@ -1873,10 +1873,6 @@ static void __target_execute_cmd(struct se_cmd *cmd)
 
         if (cmd->execute_cmd)
                 error = cmd->execute_cmd(cmd);
-        else {
-                error = cmd->se_dev->transport->execute_cmd(cmd, cmd->t_data_sg,
-                                cmd->t_data_nents, cmd->data_direction);
-        }
 
         if (error) {
                 spin_lock_irq(&cmd->t_state_lock);